The long range objective of the proposed research is to apply image processing technology to the development of an automated ophthalmic instrument that will rapidly measure the alignment of both eyes in primary gaze and quantitatively determine phorias and tropias for the ophthalmologist, the optometrist and the pediatrician as part of the routine office eye examination of children and adults. With the present methods of testing eye alignment credible results depend upon the skill of the examiner. The proposed instrument, the Trophorometer, will provide consistent reliable measurements independent of the examiner skill. The Trophorometer will use two CCD cameras, a digitizer, a computer and a printer. The patient focuses on a fixation light midway between the CCD cameras and an initial eye position is recorded. Cover-uncover and alternate cover testing is done and the position of the just uncovered eye is recorded as well as its direction of movement, if any. An alignment diagnosis is printed. The Trophorometer will also provide palpebral fissure widths, corneal diameters, interpupillary distance, and pupillary sizes. Phase I will consist of software and optical engineering development. Phase II will consist of developing software to measure secondary gaze positions, to develop an expert interpretation system and to construct and clinically test a preproduction prototype Trophorometer.